- PEP8 cleaning

- add try/catch exception for most frequent cases
 - catch key_value errors
 - catch socket error for carbon connection
 - catch for multiple exception in multigraph
 - catch exception for hello string read

m2g-poller.py

@@ -15,6 +15,7 @@ RE_LEFTRIGHT = re.compile(r"^(?P<left>\S+)\s+(?P<right>\S+)$")
 
 ## TODO: Catch keyboard interrupt properly and die when requested
 
+
 class Munin():
     """Munin host object with querying getter functions."""
     def __init__(self, hostname, port=4949, args=None):
@@ -22,6 +23,9 @@ class Munin():
         self.port = port
         self.args = args
         self.displayname = self.hostname.split(".")[0]
+        self._sock = None
+        self._conn = None
+        self.hello_string = None
 
         if self.args.displayname:
             self.displayname = self.args.displayname
@@ -39,15 +43,18 @@ class Munin():
     def connect(self):
         """Initial connection to Munin host."""
         try:
-            self._sock = socket.create_connection((self.hostname, self.port),
+            self._sock = socket.create_connection((self.hostname, self.port), 10)
-                                                  10)
         except socket.error:
             logging.exception("Unable to connect to Munin host %s, port: %s",
                               self.hostname, self.port)
             sys.exit(1)
 
+        try:
             self._conn = self._sock.makefile()
             self.hello_string = self._readline()
+        except socket.error:
+            logging.exception("Unable to communicate to Munin host %s, port: %s",
+                              self.hostname, self.port)
 
     def close_connection(self):
         """Close connection to Munin host."""
@@ -73,7 +80,7 @@ class Munin():
     def fetch(self, plugin):
         """Fetch plugin's data fields from Munin."""
         self._sock.sendall("fetch %s\n" % plugin)
-        response = { None: {} }
+        response = {None: {}}
         multigraph = None
         multigraph_prefix = ""
         for current_line in self._iterline():
@@ -83,9 +90,12 @@ class Munin():
                 response[multigraph] = {}
                 continue
             # Some munin plugins have more than one space between key and value.
+            try:
                 full_key_name, key_value = RE_LEFTRIGHT.search(current_line).group(1, 2)
                 key_name = multigraph_prefix + full_key_name.split(".")[0]
                 response[multigraph][key_name] = key_value
+            except (KeyError, AttributeError):
+                logging.info("plugin multi_graph %s returns invalid data for host %s\n ", multigraph, self.hostname)
 
         return response
 
@@ -100,7 +110,7 @@ class Munin():
     def get_config(self, plugin):
         """Get config values for Munin plugin."""
         self._sock.sendall("config %s\n" % plugin)
-        response = { None: {} }
+        response = {None: {}}
         multigraph = None
 
         for current_line in self._iterline():
@@ -127,7 +137,6 @@ class Munin():
 
         return response
 
-
     def process_host_stats(self):
         """Process Munin node data, potentially sending to Carbon."""
         start_timestamp = time.time()
@@ -147,16 +156,19 @@ class Munin():
             logging.debug("Plugin Data: %s", plugin_data)
             if self.args.carbon:
                 for multigraph in plugin_config:
+                    try:
                         self.send_to_carbon(epoch_timestamp,
                                             current_plugin,
                                             plugin_config[multigraph],
                                             plugin_data[multigraph])
+                    except KeyError:
+                        logging.info("plugin returns invalid data:\n plugin_config: %r host %s.",
+                                     plugin_config, self.hostname)
         end_timestamp = time.time() - start_timestamp
         self.close_connection()
         logging.info("Finished querying host %s (Execution Time: %.2f sec).",
                      self.hostname, end_timestamp)
 
-
     def send_to_carbon(self, timestamp, plugin_name, plugin_config, plugin_data):
         """Send plugin data to Carbon over Pickle format."""
         carbon_host, carbon_port = self.args.carbon.split(":")
@@ -169,11 +181,14 @@ class Munin():
                      plugin_name, timestamp)
 
         for data_key in plugin_data:
+            try:
                 plugin_category = plugin_config["graph_category"]
                 metric = "%s%s.%s.%s.%s" % (prefix, self.displayname, plugin_category, plugin_name, data_key)
                 value = plugin_data[data_key]
                 logging.debug("Creating metric %s, value: %s", metric, value)
                 data_list.append((metric, (timestamp, value)))
+            except KeyError:
+                logging.info("plugin returns invalid data:\n plugin_config: %r host %s.", plugin_config, self.hostname)
 
         if self.args.noop:
             logging.info("NOOP: Not sending data to Carbon")
@@ -184,11 +199,17 @@ class Munin():
         payload = pickle.dumps(data_list)
         header = struct.pack("!L", len(payload))
         message = header + payload
+        try:
             carbon_sock = socket.create_connection((carbon_host, carbon_port), 10)
             carbon_sock.sendall(message)
             carbon_sock.close()
             logging.info("Finished sending plugin %s data to Carbon for host %s.",
                          plugin_name, self.hostname)
+        except socket.error:
+            logging.exception("Unable to connect to Carbon on host %s, port: %s",
+                              carbon_host, carbon_port)
+            sys.exit(1)
+
 
 def parse_args():
     """Parse command line arguments."""
@@ -202,11 +223,13 @@ def parse_args():
                         help="Munin host to query for stats. Default: %(default)s")
     parser.add_argument("--displayname",
                         default=False,
-                        help="If defined, use this as the name to store metrics in Graphite instead of the Munin hostname.")
+                        help="If defined, use this as the name to store metrics in Graphite instead of the Munin"
+                             " hostname.")
     parser.add_argument("--interval",
                         type=int,
                         default=60,
-                        help="Interval (seconds) between polling Munin host for statistics. If set to 0, exit after polling once. Default: %(default)s")
+                        help="Interval (seconds) between polling Munin host for statistics. If set to 0, exit after "
+                             "polling once. Default: %(default)s")
     parser.add_argument("--noop",
                         action="store_true",
                         help="Don't actually send Munin data to Carbon. Default: %(default)s")
@@ -218,7 +241,7 @@ def parse_args():
                         action="store",
                         default="servers",
                         help="Prefix used on graphite target's name. Default: %(default)s")
-    parser.add_argument("--verbose","-v",
+    parser.add_argument("--verbose", "-v",
                         choices=[1, 2, 3],
                         default=2,
                         type=int,
@@ -227,16 +250,17 @@ def parse_args():
     args = parser.parse_args()
     return args
 
+
 def main():
     args = parse_args()
     if args.verbose == 1:
-        LOGGING_LEVEL = logging.ERROR
+        logging_level = logging.ERROR
     elif args.verbose == 3:
-        LOGGING_LEVEL = logging.DEBUG
+        logging_level = logging.DEBUG
     else:
-        LOGGING_LEVEL = logging.INFO
+        logging_level = logging.INFO
 
-    logging.basicConfig(format=LOGGING_FORMAT, level=LOGGING_LEVEL)
+    logging.basicConfig(format=LOGGING_FORMAT, level=logging_level)
     munin = Munin(hostname=args.host, args=args)
     munin.go()